Identification of the RNAi core machinery in Lepidoptera species

It was shown, that RNAi in Lepidopteran is not as straight-forward as for other insects and it has been proven to be difficult to establish. There have been several studies done in the past years with RNAi in different moth species which were sometimes successful and sometimes not (1). An important role in that random success could be the tissue in which a gene should be silenced, and also how the dsRNA is delivered to that tissue. To address these questions I want to identify the genes which are involved in the RNAi pathways (miRNA-pathway and siRNA-pathway) and in the transport or spreading of dsRNA in Helicoverpa armigera, Heliothis virescens and Spodoptera frugiperda and analyse the expression level of these RNAi core machinery genes in different tissues.